Process of preparing anthrimides



Patented Mar. 25, 1952 PROCESS OF PREPARING ANTHRIMIDES Mario Scalera,Somerville, and Hugh W. Stewart,

Plainfield, N. J assignors to American Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Application July 7, 1950, SerialNo. 172,622

i3 Claims.

This invention relates to the manufacture of alpha,beta anthrimides fromalpha halogen anthraquinone and beta aminoanthraquinone compounds havingthe following formulae:

HalOY zoz llll I ll! NHz Y t Y Z t Z in which Hal represents a halogen,such as chlorine, bromine and iodine, Z represents monovalent inertsubstituent selected from the class consisting of hydrogen and anunreactive substituent group, such as acylamino, alkyl and alkoxygroups, one Y is selected from the group consisting of Hal and Z, andthe other Ys are Z, and one X is Z and the other X is selected from thegroup consisting of NH2 and Z, and it comprises new and improved methodsfor producing alpha, beta anthrimides wherein said alpha-halogenanthraquinone and said beta amino compounds are reacted together in anorganic solvent in the presence of an acid binding agent suificient toreact with the hydrogen halide set -.free and in the presence of acupriferous catalyst containing copper and iodine in the ratio of from0.9 to 2.0 atoms of iodine per atom of copper.

Anthrimides have been produced in the past by. the well-known Ullmannreaction in which a halogen anthraquinone is reacted with anaminoanthraquinone, usually in an inert organic solvent and in thepresence of an acid binding agent.

Cupriferous catalysts are normally used, the comyields are nearlyquantitative and the various cupriferous catalysts are equivalent.Alpha,betaanthrimides, however, have presented a serious problem. In thepast the only practical method involved the reaction of analpha-aminoanthraquinone with a beta-chloroanthraquinone. The aboverestriction has been a very serious drawback, particularly when it isdesired to 'produce substituted a1pha,beta-anthrimides. In many cases itis more convenient to prepare beta-amino and alpha-halogenointermediates, rather than vice versa. Thus, for example, when preparingalpha,beta-trianthrimides of the formula:

it would be much more economical to use 2,6-diaminoanthraquinone than touse the 2,6-dichlor or dibromo derivatives which are much more difiicultto prepare.

By the present invention, alpha,beta anthrimides can be readily preparedfrom alpha halogen anthraquinones and beta-aminoanthraquinones byreacting the same together inthe presence of a cupriferous catalystcontaining copper and iodine in the ratio of 0.9 to 2.0 atoms of iodineper atom of copper. In other words, we have found that said cupriferouscatalysts are very effective condensing agents in this particularreaction and so facilitate the reaction as to produce high yields ofalpha,beta-anthrimides substantially free of impurities as fully setforth post. The discovery represents an important advance in thecommercial art and was described in our prior co-pending applicationSerial No. 618,583, filed September 25, 1945, now abandoned, the presentapplication being a continuation-impart thereof.

According to the present invention, alpha,betaanthrimides are obtainedby reacting an alphahalogenoanthraquinone of the formula:

ICIJ Hal where Hal stands for chlorine, bromine and iodine, one Y isselected from the group consisting of Hal and Z, and Z is selected fromthe group consisting of hydrogen and a substituent unreactive underUllmann conditions, with a betaaminoanthraquinone of the formula:

Z Z N in which one X is selected from the group consisting of amino andZ, the other X is Z, and Z is selected from the above-given group. Amongthe unreactive groups are such groups as acyljagent but the catalystmust be one containing copper and iodine in the proportions of fromslightly less than one, i. e. about 0.9, to two mols of iodine per molof copper. In other words, the iodine content ranges from slightly lessthan that corresponding to cuprous iodide up to that corresponding tocupric iodide. The use of the term slightly less than one mol as appliedto iodine will be used throughout the following specification and claimsto mean amounts not materially less than 0.9 mol. The efficiency of theprocess drops off as the upper limit of two mols of iodine isapproached, larger amounts of iodine appear in part as free iodine andcause an even more marked falling off in yield. In general the rangefrom slightly less than a mol to about a mol and a quarter representsthe optimum range though this will vary somewhat with differentreactants.

The reaction of the present invention does not follow standard Ullmannreaction experience.

The ordinary commercial Ullmann catalysts, such as cupric chloride, givesuch low yields as to be quite useless, and cuprous chloride givesresults that are only slightly, if any, better. On the other hand, thecopper-iodine catalysts of the present invention ive excellent yields,and in the present reaction are in no sense the equivalents of chloridesof copper. The copper and iodine ratios have been referred to inconnection with known compounds. However, it is in no sense necessary toadd the copper and iodine as a preformed salt such as cuprous iodide. Onthe conin the reaction mixture when less than two atoms ingly improvedresults over the standard copper.

chloride Ullmann catalysts may be due to other factors not fully knownat present. It is also not known why the copper-iodine catalysts do notshow improved results in the other Ullmann reactions when compared tocupric chloride. Apparently the copper-iodine catalyst acts in adifferent manner with beta-amino groups than with alpha-amino groups.Just what the nature of this different reaction may be is not known.

It is an advantage of the present invention that the amount of catalystis not critical. We have found that minute amounts of catalyst areineffective. In general, about 0.1 mol of copper per mol ofbeta-aminoanthraquinone represents the lower limit of practicaloperation. It may well be that the catalyst actually enters into thereaction and is continuously regenerated, so that it is more in thenature of a condensing agent than a pure catalyst. The two terms aretherefore used in the present case in their more general equivalentsense. Excessive amounts of catalyst merely waste copper and iodine and,in general, the optimum results are obtained in the range of 0.1-1.0 molcopper per mol of betaaminoanthraquinone. In its more specific aspectsthe present invention includes this range of condensing agent.

It is an additional advantage of the present invention that there are nocritical solvents. The

usual inert solvents which are employed in other Ullmann reactions areuseful. They should, of course, be inert to the conditions of thereaction at the elevated temperatures in the range of -250 which areoften attained. Nitrobenzene, which is feasible and satisfactory, isconsidered the preferred solvent. It is also possible to operate withoutany solvent, but ease of mechanical manipulation makes solvent ordiluent desirable. The process of the present invention operateseffectively with any beta-aminoanthraquinone. free from reactivesubstituents. Suitable reactants include Z-aminoanthraquinone, 2-amino-5-benzoylaminoanthraquinone, 2,6-diaminoanthraquinone, 3methyl-2-aminoanthraquinone, 2,7-diaminoanthraquinone, and3-methoxy-2-amin0anthraquinone.

- desirable because they are not inert under the conditions of thereaction.

The invention will be described in greater detail in the followingspecific examples, the parts being by weight.

. Example 1 ofimcolyH i H I i NH- NH. 0 I II II 0 i NHOCtH Into 1,520parts of nitrobenzene are slurried the following chemicals: 152 parts ofl-chloro- 5-benzoylaminoanthraquinone, 47.6 parts of 2,6-diaminoanthraquinone, 85 parts of soda ash, 10.2 parts of copper powderand 25.4 parts of iodine. The resulting slurry is heated with stirringat the refluxing temperature, 210 C., for 24 hours. After cooling, theproduct is filtered, washed with nitrobenzene, alcohol and water, anddried.

There are obtained 156 parts of a bright redbrown product, correspondingto a yield of 88% of the theoretical.

The product dissolves in concentrated sulfuric acid with a bright greencolor, and is precipitated by dilution as red-brown flocs. It dyescotton from the vat a bright red-brown shade.

The same results are obtained if the copper powder and iodine arereplaced by 30.6 parts of cuprous iodide and 5.0 parts of iodine.

The effect of varying proportion of iodine in the cupriferous catalystis illustrated in the table 1 Very impure.

1 Impure.

If cuprous chloride is used in place of copper and iodine in the abovereaction, the crude yield is 45%, and the product is largely unchanged2,6-diaminoanthraquinone. If cupric chloride is employed in the place ofthe copper and iodine, a 50% yield of a very impure product results.

Example .2

152 parts of 1-chloro-5-benzoylaminoanthraquinone, 47.6 parts of2,-6-diaminoanthraquinone, 66 parts of anhydrous sodium acetate, 10.2parts of copper powder, and 25.4 parts of iodine are suspended in 3,000parts of nitrobenzene. The slurry is heated to the boil (210 C.) andheld at this temperature under reflux for 24 hours.

After cooling, the product is isolated by filtration, and washed withnitrobenzene and alcohol. It is then treated with steam to remove allnitrobenzene, filtered, washed with water and dried. The yield is 128parts, or 72% of the theoretical. The product is identical with thatdescribed in Example 1.

Erample 3 23.8 parts of 2,6-diaminoanthraquinone, 52 parts ofl-chloroanthraquinone, 50 parts of anhydrous sodium carbonate, 51 partsof copper powder, 12.7 parts of iodine and 900 parts of nitrobenzene areheated at the reflux temperature (210 C.) for about 24 hours. Theredbrown slurry is filtered when cool, and the filter cake is washedwith nitrobenzene and alcohol. The cake is finally steamed free oftraces of nitrobenzene, from an acid slurry.

The product is obtained in quantitative yields by filtering, washing anddrying.

The dye is red-brown in color, is bright green in concentrated sulfuricacid, and dyes cotton a reddish brown shade from a red-brown vat.

A much lower yield of inferior quality product is obtained if cupricchloride is used as the catalyst instead of the copper and iodine asabove described.

Example 4 0 II I cunooNn 0 NH- -l| IH NHCOUtH II o 304 parts of1-chloro-8-benzoylaminoanthra quinone, 95.2 parts of2,G-diaminoanthraquinone, 1'70 parts of soda ash, 20.4 parts of copperpowder, and 50.8 parts of iodine are introduced into 3,600 parts ofnitrobenzene. The slurry is heated with stirring to the boilingtemperature, and maintained under reflux at that temperature for 24hours.

After cooling, the product is isolated by filtration and washed withnitrobenzene. The press cake is steam stripped free of nitrobenzene,filtered, washed and dried.

There are obtained 284 parts of product or a yield of of thetheoretical. The product dissolves in concentrated sulfuric acid with agreen color, and dyes cotton a bright red-brown shade, considerablybluer than the product of Example 1.

If in the above example 1-chloro-4-benzoylaminoanthraquinone is used inplace of the 1- 7 chloro-8-benzoylaminoanthraquinone, there is obtaineda dark product, the 4,4"-dibenzoylamino-1,2-6',1"-trianthrimide. Thisproduct dissolves in concentrated sulfuric acid with a green color, anddyes cotton from the vat a bluish brown, very level shade, which showsvery good properties of fastness.

In both of the above reactions, inferior results are obtained whencupric chloride is used as the catalyst.

. Example 5 0 I H X N11- Where one X and one Y stand for CeH5CONH-, theother X and the other Y being hydrogen.

304 parts of a technical mixture of 1,5- and1,8-chlorobenzoylaminoanthraquinone (obtainable by the successivechlorination, reduction and benzoylation of the nitration product ofanthraquinone-l-sulfonic acid) are slurried in 3,600 parts ofnitrobenzene. To this slurry are added 95.2 parts of 2,6-diaminoanthraquinone, 200 parts of iodine. The slurry is heated to the boilingpoint with agitation, and kept at the boiling temperature for 24 hoursunder reflux.

After cooling, the mass is filtered, washed with nitrobenzene, and thecake is freed from nitrobenzene by steam. The product is filtered anddried.

The yield is 314 parts, or 88.5% of the theoretical, of a brightred-brown product. -Ihe product may be purified further, if desired, bydissolving it in 20 parts of concentrated sulfuric acid, diluting thesolution to 20% acid strength, and oxidizing the resulting red-brownslurry with sodium dichromate. The product thus obtained dyes cottonfrom the vat a rich red-brown shade of outstanding fastness properties.

The yield of product obtained in this reaction,

' shows a dependence on the iodine-to-copper ratio similar to thatdescribed in Example 1. The use of cupric chloride, instead, gives muchinferior results.

Example 6 CtHsCONH O 55.6 parts of 2-aminoanthraquinone, 90.5 parts of1-chloro-4-benzoylaminoanthraquinone, 53 parts of soda ash, 16 parts ofiodine, 6.4 parts of copper powder, and 1,600 parts of nitrobenzene aremixed and heated with stirring to the refluxing temperatures. Thistemperature is maintained under reflux for 24 hours.

After cooling, the product is isolated by filtration, washed withnitrobenzene and steam distilled free of solvent.

The yield of dry product is 96 parts, or 71% of the theoretical. It dyescotton from the vat a Corinth shade.

Inferior results, with respect to both yield and purity, are given whencupric chloride is used as a catalyst.

Example 7 where one X is CeH5CONH- and the other X is hydrogen.

362 parts of a technical mixture of 1,5- and1,8-chlorobenzoylaminoanthraquinone (prepared, for instance, asdescribed in the first paragraph of Example 5) are slurried in 6,000parts of nitrobenzene. To this slurry are added 223 parts of2-aminoanthraquinone, 212 parts of soda ash. 25.6 parts of copperpowder, and 64 parts of iodine.

The slurry is heated with agitation to the boiling temperature, and heldat this temperature for 24 hours. It is filtered after cooling. Thebrown product is washed with nitrobenzene, then with alcohol, andfinally freed of all traces of solvent by means of steam, and dried.

The yield is 387 parts, or 71% of the theoretical. The product dyescotton a brown shade of good fastness from a hydrosulfite bath.

If, in the above experiment, one-half the quantity of iodine is used (32parts), all other usages remaining the same, the yield of productobtained is only 207 parts, or 39% of the theoretical.

Example 8 where one X represents CsH5CONH and the other represents H.

To 360 parts of nitrobenzene are added 17.8 parts of2-aminoanthraquinone, 20 parts of sodium carbonate, 2.0 parts of copper,5.1 parts of iodine, and 30.4 parts of a mixture of l-chloro-5-benzoylamino and l-chloro-8-benzoylaminoanthraquinone. The resultingslurry is refluxed 24 hours, cooled, filtered, and washed with 480 partsof nitrobenzene. The product is steam disstilled free of nitrobenzene,slurried in alcohol, filtered, washed, and dried. The yield of redbrownanthrimide is 33.0 parts, or over 75% of the theoretical.

If the copper and iodine in the above reaction are replaced by 4.1 partsof anhydrous cupric chloride, the yield of product is only about 20%,and the product is much inferior in quality.

Example 9 A mixture of 19.1 parts of 2,6-diaminoanthraquinone, 23.3parts of 1,5-dichloroanthraquinone, 360 parts of nitrobenzene, 40 partsof anhydrous sodium carbonate, 4.1 parts of copper powder, and 10.2parts of iodine, is refluxed for 24 hours, cooled and filtered. The cakeis washed with 480 parts of nitrobenzene, then steam stripped free ofsolvent, slurried in alcohol, and filtered, washed and dried. Theproduct is further purified by acid pasting from 18 times its weight ofconcentrated sulfuric acid, followed by heating in ammonium hydroxidesolution, filtering, and washing. 37.9 parts of tetranthrimide areobtained, representing a quantitative yield of 102%, the tetranthrimidecontaining a small amount of anthramides of other molecular weights. Itis a brown product which dyes cotton in reddishbrown shades.

When the amount of iodine is reduced to 8.1 parts, the yield obtained is98%. Replacing the copper-iodine catalyst with 8.2 parts of anhydrouscupric chloride reduces the yield to about 57%, and the product givesweak tan dyeings.

Example 10 OCHa A mixture of 95.5 parts of 2,6-diaminoanthraquinone, 228parts of l-chloroi-methoxyanthraquinone, 1800 parts of nitrobenzene, 200parts of sodium carbonate, 20.5 parts of powdered copper, and 50.8 partsof iodine, is refluxed for 24 hours, cooled and filtered. The product isWashed with nitrobenzene, freed of solvent by steam stripping, thenslurried in hot ammonia solution, filtered, washed and dried. A yield of227 parts, or 80% of theoretical, is obtained, of a blue-black powderwhich gives violet-brown dyeings.

If the copper and iodine are replaced by 41 parts of anhydrous cupricchloride, the yield of product is only about 57%.

10 The improvement in yield and purity of product obtained by the use ofthe iodine-containing cupriferous catalyst of the present invention willvary to some extent with different dyestufis. However, in the case ofeach of the types of anthrimides described in the examples, markedimprovement in yield and purity can be noted. The following tablesummarizes the examples where the improvements in yield are set forthnumerically:

y Cu-I Per CllClz Per Eiampl Cent Yield Cent Yield Dianthrimida 8 75 2O'lrianthrimide. 1 1 82-90 50 D 0 1 1 l 0 S0 57 D0 9 98-102 I 57 Weclaim:

1. As a new and improved method of producing alpha, beta anthrimides bythe Ullmann reaction from alpha halogen anthraquinone and in which Halrepresents a halogen, Z represents a monovalent inert substituentselected from the class consisting of hydrogen and a substituent groupunreactive under Ullmann conditions, one Y is selected from the groupconsisting of Hal and Z, and the other Ys are Z, and one X is Z and theother X is selected from the group consisting of NH2 and Z; the improvedmethod which comprises reacting said beta aminoanthraquinone compoundswith said alpha-halogenanthraquinone in an organic solvent in thepresence of an acid binding agent suificient to react with the hydrogenhalide set free and in the presence of a cupriferous catalyst containingcopper and iodine in the ratio of from 0.9 to 2.0

' atoms of iodine per atom of copper.

2. A method according to claim 1 in which the catalyst contains from 1.1to 1,8 atoms of iodine per atom of copper.

3. A method according to claim 2 in which the unreactive groups arealpha-aroylamino and at least one Z on the alpha-halogen anthraquinoneis aroylamino.

4. A method according to claim 3 in which the aroylamino group isbenzoylamino.

5. A method according to claim 4 in which the reaction takes place innitrobenzene as a reaction medium.

6. A method according to claim 1 in which the reaction takes place innitrobenzene as a reaction medium.

'7. A method according to claim 1 in which the beta-aminoanthraquinoneis 2,6-diaminoanthraquinone.

8. A method according to claim '7 in which the halogen anthraquinone isalpha-chloroanthraquinone.

9. A method according to claim 7 in which the reaction takes place innitrobenzene as a reaction medium.

10. A method according to claim 1 in which the beta-aminoanthraquinoneis 2,6-diaminoanthraquinone and the alpha-halogen anthraquinone isalpha-chloroanthraquinone and the acid binding agent is sodiumcarbonate.

11. A method of producing an anthrimide which comprises reacting2,6-diamino anthraquinone with alpha halogen alpha benzoyl-aminoanthraquinones having no other substituents in an organic solvent in thepresence of an acid binding agent sufi'icient to react with the hydrogenhalide set free and in the presence of a cupriferous catalyst containingcopper and iodine, the amount of iodine being more than 1 but less than2 atoms per atom of copper.

'12. A method of producing an anthrimide which comprises reacting2,6-diamino anthraquinone with an alpha halogen alpha benzoylaminoanthraquinone having no other substituents in nitrobenzene in thepresence of an acid binding agent sufiicient to react with the hydro-MARIO SCALERA. HUGH W. STEWART.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 961,612 Isler June 14, 19101,974,866 Hauser et a1. Sept. 25, 1934 2,174,751 Koeberle et al. Oct.3,1939

FOREIGN PATENTS Number Country Date 9,219 Great Britain Jan. 2'7, 191025,986 Great Britain Aug. 4, 1910 29,138 Great Britain Dec. 13, 1910OTHER REFERENCES In re Wuertz et al., 27 C. C. P. A. 1039, 1940, C. D.377, 519 O. G. '7.

1. AS A NEW AND IMPROVED METHOD OF PRODUCING ALPHA, BETA ANTHRIMIDES BYTHE ULLMANN REACTION FROM ALPHA HALOGEN ANTHROGUINONE BETA-AMINOANTHRAQUINONE COMPOUNDS HAVING THE FOLLOWING FORMULAE: